I know or think the big twin cylinder engines can be noisy at times but lately i just noticed my hobart is a little noisy with a slight rattle. I'm not too familair with these heavy duty twin cylinder engines so is it normal?? It almost sounds like a ping type noise. But she runs awesome. No smoke and great compression. I was thinking maybe the valves need adjusting? Its not a knock type noise. I know the valves on the old gravely l head were very noisy too.

I'm technically misunderstood at times i guess its been this way my whole life so why should it change now.

The 2-cylinder Wisconsin engines I used were back in the 1950s. Flat head (valve-in-block) inline, air cooled. It is widely believed that flat head engines have a greater tendency to "spark knock" than do OHV engines of comparable compression. And air cooled engines run hotter than do liquid cooled ones. Hot surfaces can cause preignition. Using higher octane fuel to test it is not going to harm anything except your wallet.

You guys are right again. My son got me a can of regular gas fror it. It sounds like a ping now. I did add a can of seafoam in the tank too. I'll gas her up with high test and wait till the next blackout.

I haqd over 20 gallons of high test gas and i'm down to 8 gallons left for running this big machine for a week thats not bad.

She needs and diserves a full tune up now too. I'm sure she hasn't been tuned in eons. I just sandpaper the points and gap them by eye to make it run for now. You guys have to be always right i need to time it too and go thru it all completely. I need to fab a little trailer so my cadet can tow it too.

I'm technically misunderstood at times i guess its been this way my whole life so why should it change now.